The document U.S. Pat. No. 5,076,687 discloses a multi-image capture system comprising:                a converging lens able to receive light from objects in an object field and to direct said received light to an image field of the converging lens;        a plurality of micro-lenses distributed about the image field of the converging lens such that each micro-lenses receives light from the converging lens and forms an image from the light it receives;        a photodetector array divided into a plurality of macropixels each of which is subdivided into a plurality of pixels, each macropixel receiving an image formed by one of the micro-lenses such that each pixel of a macropixel receives light from one portion of the converging lens as imaged by one of the micro-lenses, each pixel being able to generate an image data indicative of the intensity of light incident upon it;        and a data processor able to build a plurality of so-called “depth-images” of said objects in the object field, such that each image is built from image data generated by pixels having like spatial positions within the different macropixels of the photodetector array.        
See also document DE 3018470 (SIEMENS) where the capture system comprises also a beamsplitter positioned on the optical path between the imaging lens and the array of micro-imaging elements to redirect a second portion of the light received from the imaging lens to a second image field (ref. 33) of the imaging lens.
See also document US 2006/221209 disclosing a tree diagram of acquisition of a plenoptic field originating from a scene, where nodes with multiple child nodes of this diagram represents beam splitters and leaf nodes represent image sensors.
The data processor is also able to compare the parallax between the different depth-images in order to determine depth of said objects in the object field.
Each depth image is representative of light passing through a different region of the converging lens, and then gives an image of the object field under a different angle of view.
Generally:                there is one macropixel for each image generated by a micro-lens;        each macropixel comprises the same number of pixels;        in all macropixels, the pixels are spatially distributed similarly;        the microlenses are arrayed in a rectangular lattice, corresponding to the format of each of the plurality of depth images.        
In a different image capture device, U.S. Pat. No. 7,199,348 proposes also to use the parallax that has been determined between different views of a same object field to map the depth of the objects within this field.
As disclosed in U.S. Pat. No. 5,076,687, the number of pixels in each macropixel determines the number of different depth images though the converging lens of the multi-image capture system, and the number of microlenses determines the spatial resolution of these depth images.
Presently, the number of pixels in the photodetector array is a limitation for the spatial resolution of the depth map of the object field that can be obtained by comparing the parallax between the different depth-images. In the article entitled “Light Field Photography with a Hand-held Plenoptic Camera”, authored by Ren Ng, Marc Levoy, Mathieu Brédif, Gene Duval, Mark Horowitz and Pat Hanrahan, published in the Standford Technical Report CTSR, on February 2005, a Kodak KAF-16802CE photodetector array of 4000×4000 pixels is used in conjunction with an array of 296×296 microlenses. But using such high resolution photodetector array is very expensive although the resolution of each of the depth image (i.e. 296×296) remains unacceptably low.